The word for “puzzle” in Spanish is “rompecabezas”—literally, a head breaker. The term serves as an apt description of Mexico City’s hydrologic tangle, a multi-faceted conundrum that exemplifies the global need to make water systems sustainable.
Legend has it that Mexico City was founded in a sacred location. For more than two centuries, the Mexica people migrated in search of the promised land—a place where their gods said they would find an eagle perched in a cactus holding a snake in its mouth. When they discovered that place in 1395, it happened to be on an island in the middle of a lake.
Over the centuries since Mexico City’s founding, its conquest by the Spaniards, and urbanization, the city has expanded exponentially. Elaborate engineering projects have been designed to drain the lake’s water to allow urban expansion. Tunnels from the 1950s-era Deep Drainage System crisscross beneath the city to carry floodwater and urban runoff to the city’s outskirts. But today the mountain-ringed valley still fills up when it rains.
In addition to the city’s drainage issues, is the fact that drinking water for its 20 million residents comes from a below-ground aquifer. As the aquifer is depleted, the clay lakebed compacts and the city sinks—by a reported 15 inches a year in some areas. This dramatic subsidence has severely damaged infrastructure. As a result of line breaks and other age-related issues, Mexico City’s water distribution pipelines lose a startling 40% of the water they convey.
Today, many people living in the city center have no access to water for weeks on end. And when they do, it is delivered via tanker truck.
Ramón Aguirre Díaz, who has run Mexico City’s municipal water system for more than a decade, recently told NPR, “We are depleting volumes of water that took hundreds, thousands of years to store. Sooner or later it will run out.”
Hydrologists agree that Mexico City would benefit from a more sustainable approach to its water system. Dean Chahim, a Ph.D. candidate at Stanford who studies Mexico City’s water puzzle, believes that there is a strong need for water recycling and aquifer recharge. He views Mexico City’s multifaceted water puzzle as a single-city example of a larger, global-scale issue.
What are your impressions? How can Mexico City engineer a more sustainable water system? How can the city provide water to residents without over-taxing aquifers or hauling it over long distances? How can these solutions be applied to other cities around the world?
We will discuss solutions to water scarcity and the importance of balancing hydrologic systems at the Western Water Summit, February 6–7 in San Diego, CA. It promises to be a dynamic event that offers practical insight and real-world solutions. We hope that you’ll join the conversation.